a)\(\frac{-5}{6}\).\(\frac{120}{25}\)<x<\(\frac{-7}{15}\).\(\frac{9}{14}\)

       -4                 <x<\(\frac{-3}{10}\)

\(\frac{-40}{10}\)<      x   <\(\frac{-3}{10}\)=>x E {-39:-38:-37:.....:-4}

b)\(\left(\frac{-5}{3}\right)^3\)<x<\(\frac{-24}{35}.\frac{-5}{6}\)

\(\frac{-875}{189}< x< \frac{108}{189}\)

=> x  E {\(\frac{-874}{189},\frac{-873}{189},......,\frac{107}{189}\)}

\(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)

<=>  \(-4< x< -0,3\)

p/s: do k biết điều kiện của x nên mk làm đến đó

      chúc bạn học tốt

1)

a)

\(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)

\(\frac{-1}{1}.\frac{20}{5}< x< \frac{-1}{5}.\frac{3}{2}\)

\(\frac{-20}{5}< x< \frac{-3}{10}\)

\(\frac{-40}{10}< x< \frac{-3}{10}\)

\(\Rightarrow Z\in\left\{-4;-5;-6;-7;-8;-9;-10;...;-39\right\}\)

\(\left(\frac{-5}{3}\right)^3< x< \frac{-24}{35}.\frac{-5}{6}\)

\(\frac{25}{3}< x< \frac{-4}{7}.\frac{1}{1}\)

\(\frac{-25}{3}< x< \frac{-4}{7}\)

\(\frac{-175}{21}< x< \frac{-12}{21}\)

\(\Rightarrow Z\in\left\{-13;-14;-15;-16;...;-174\right\}\)

2)

a)

\(\left(\frac{9}{10}-\frac{15}{16}\right).\left(\frac{5}{12}-\frac{11}{15}-\frac{7}{20}\right)\)

\(=\left(\frac{72}{80}-\frac{75}{80}\right).\left(\frac{25}{60}-\frac{44}{60}-\frac{21}{60}\right)\)

\(=\frac{-3}{80}.\frac{-40}{60}\)

\(=\frac{-1}{-2}.\frac{-1}{-20}\)

\(=\frac{1}{40}\)

Bài 1: Tìm x biết:

1) x +\(\frac{7}{12}\)= \(\frac{17}{18}\)- \(\frac{1}{9}\)                                                                               2) \(\frac{29}{30}\)- (\(\frac{13}{23}\)+ x) = \(\frac{7}{69}\)

 x +\(\frac{7}{12}\)= \(\frac{15}{18}\)                                                                                                                \(\frac{13}{23}\)+ x = \(\frac{29}{30}\)- \(\frac{7}{69}\)

             x = \(\frac{15}{18}\)- \(\frac{7}{12}\)                                                                                                    \(\frac{13}{23}\)+ x = \(\frac{199}{230}\)

             x = \(\frac{1}{4}\)                                                                                                                                   x = \(\frac{3}{10}\)

1) \(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)

\(\Leftrightarrow\frac{-5}{6}.\frac{24}{5}< x< \frac{-63}{210}\)

\(\Leftrightarrow-40< x< \frac{-63}{210}\)

\(\Leftrightarrow\frac{-400}{10}< \frac{10x}{10}< \frac{-3}{10}\)

\(\Leftrightarrow-400< 10x< -3\)

\(\Leftrightarrow x\in\left\{-39;-38;...;-2;-1\right\}\)

2) \(\left(\frac{-5}{3}\right)^3< x< \frac{-24}{35}.\frac{-5}{6}\)

\(\Leftrightarrow\frac{-125}{25}< x< \frac{4}{7}\)

\(\Leftrightarrow\frac{-35}{7}< \frac{-7x}{7}< \frac{4}{7}\)

\(\Leftrightarrow-35< -7x< 4\)

\(\Leftrightarrow x\in\left\{4;3;2;1;0\right\}\)

vế trái có bị sai ko em. chị nghĩ câu hỏi nên là: x+2/17 + x+4/15 + x+6/13=x+8/11 + x+10/9 + x+12/7